Guns don't kill people ....

[classicman]

Who is the fucking adult in charge here?

Thats the question I was trying to answer as well.
Legally, it is the uncle. However, I don't see how he should be held responsible for this.
IMO, the mom's boyfriend should be in serious shit for having a loaded firearm in the glove box of his car.
I wonder how the boy knew it was there and how he got access to it.
Was the frikkin car also unlocked???
A whole lotta WTF going on here.